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-   -   Long Exposure Photography on the N900 (light painting) (https://talk.maemo.org/showthread.php?t=90016)

malfunctioning 2013-05-05 19:46

Long Exposure Photography on the N900 (light painting)
 
I came across this nice video showing how some people are doing light painting with the N900: http://www.youtube.com/watch?v=e6GEE...ture=endscreen

I am really interested in this, but more to take pictures of sunset / night landscapes. Anybody here doing the same thing?

I don't think the stock camera (or even the camera in CSSU-Thumb) can control the amount of exposure. Is there some other application that does that?

Estel 2013-05-05 21:32

Re: Long Exposure Photography on the N900 (light painting)
 
fCam & friends. It need fCam drivers, to control exposure at required level. nice video, BTW.

Now, who want a littler Nokia bashing, for wasting potential like that? It's a marketing heaven (whole things about N900, not that video alone). It must have required real effort to sabotage developing on it, further.

/Estel

malfunctioning 2013-05-05 21:40

Re: Long Exposure Photography on the N900 (light painting)
 
Thank you, I'll look into fCam.

Yes, you are right. There are so many amazing things about the N900 that it almost seems impossible to screw things up (unless you do it on purpose, like you say).

By the way (slightly off topic), I just did the experiment with the camera regarding IR light sources. Took an IR remote to a completely dark room, and the N900 camera clearly sees the IR light, whereas the naked eye sees nothing at all. I think that with a powerful enough IR light source we might have functional night vision with the N900. :)

Estel 2013-05-05 22:51

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by malfunctioning (Post 1341536)
By the way (slightly off topic), I just did the experiment with the camera regarding IR light sources. Took an IR remote to a completely dark room, and the N900 camera clearly sees the IR light, whereas the naked eye sees nothing at all. I think that with a powerful enough IR light source we might have functional night vision with the N900. :)

See:
http://talk.maemo.org/showthread.php?t=86332

;)

// Edit

After finishing my N900's alternate body project, I'm planning to do something special. You see, I'm probably going to settle down on circle-cover for camera in replacement backcovers. there is no reason, why I couldn't use modified camera module (without IR filter) whole time, with one part of circle cover being just IR filter (for normal photography). This way, camera cover would have 3 states - closed, open, and open-with-IR-filter ;)

Add to this a pack fo high-power IR leds, and you have portable night-vision. Either by looking at N900 screen while keeping it in hand, or - if one want really fancy DIY kit - by hacking together a googles with mount-point for N900, and screen for view (using video output).

handaxe 2013-05-06 20:27

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by malfunctioning (Post 1341536)
By the way (slightly off topic), I just did the experiment with the camera regarding IR light sources. Took an IR remote to a completely dark room, and the N900 camera clearly sees the IR light, whereas the naked eye sees nothing at all. I think that with a powerful enough IR light source we might have functional night vision with the N900. :)

Most digital cams do this, as the IR filters are not 100% competent. Take that filter off, as estel discusses and azkay did then you get really good IR under IR illumination.

malfunctioning 2013-05-07 04:50

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by Estel (Post 1341548)
See:
http://talk.maemo.org/showthread.php?t=86332

;)

// Edit

After finishing my N900's alternate body project, I'm planning to do something special. You see, I'm probably going to settle down on circle-cover for camera in replacement backcovers. there is no reason, why I couldn't use modified camera module (without IR filter) whole time, with one part of circle cover being just IR filter (for normal photography). This way, camera cover would have 3 states - closed, open, and open-with-IR-filter ;)

Add to this a pack fo high-power IR leds, and you have portable night-vision. Either by looking at N900 screen while keeping it in hand, or - if one want really fancy DIY kit - by hacking together a googles with mount-point for N900, and screen for view (using video output).

Yeah, I read that thread. You and that other fellow sure have some courage picking on your poor N900 camera modules like that! :)

Also, interesting that at least 2 different camera module assemblies were produced. It's easy to think many other parts were the same. This was a common source of worries and expectation for IBM Thinkpad users (which manufacturer has produced which part, such as keyboard, screen, etc), as it was part of forum knowledge that some manufacturers produced far superior parts, but unfortunately it was impossible to tell beforehand which one you would get.

Yeah, that night vision project is starting to sound quite powerful.

Estel, have you thought of providing a way to fit some sort of standard camera mount to your body replacements? I suppose an N900 might get quite unwieldly with a large lense attached to it, but I've seen it done with iPhones. Just throwing that in there, don't get some crazy ideas. :)

I wonder how much light might I get from some kind of IR headlamp in total darkness without even removing the IR filter from the N900 camera.

malfunctioning 2013-05-07 04:52

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by handaxe (Post 1341719)
Most digital cams do this, as the IR filters are not 100% competent. Take that filter off, as estel discusses and azkay did then you get really good IR under IR illumination.

I think I'll test first without taking off the filter. It's surprising how bright that IR led looked in complete darkness.

pichlo 2013-05-07 13:04

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by handaxe (Post 1341719)
Most digital cams do this, as the IR filters are not 100% competent. Take that filter off, as estel discusses and azkay did then you get really good IR under IR illumination.

I wonder how this works. Physically, that is. Image sensors in digicams have an RGB filter mask that works on a pixel-by-pixel basis. I find it hard to believe that the green pixels pick up green and IR light, unless the IR is several orders of magnitude brighter than visible light. It is more likely that only the red pixels pick up any IR, but then I would expect the unprocessed resulting images look black-and-red. But most pictures I've seen (e.g. here) look black-and-white with a red tint. How come? The only explanation I have is that the camera also picks up visible light, thus activating the green and blue pixels too, but the red ones are dominant because they pick up red and IR. In other words, if you replace an IR suppress filter with IR pass-though, you would get true black-and-red as I would expect. Am I on the right track?

juiceme 2013-05-07 14:39

Re: Long Exposure Photography on the N900 (light painting)
 
Actually the sensitivity range/frequency of pixels is fairly broad, so even a "green pixel" reacts to almost the whole visible spectrum, more so on the "green hues" than other hues but if the light source is strong enough, all pixels get saturated.

Estel 2013-05-09 00:06

Re: Long Exposure Photography on the N900 (light painting)
 
Quote:

Originally Posted by malfunctioning (Post 1341777)
Estel, have you thought of providing a way to fit some sort of standard camera mount to your body replacements? I suppose an N900 might get quite unwieldly with a large lense attached to it, but I've seen it done with iPhones. Just throwing that in there, don't get some crazy ideas. :)

Yea, though about that - to be precise, I've thought about threaded circular thing'ie (in the place, where mugen cover have just useless rectangular hole for camera), that one could use to screw a mini lens (objective lens), allowing optical zoom. The problem is, that I'm not aware of any "standardized" lenses of that size, so I could put a proper, general purpose thread - most of things I've seen are either overpriced iPhone toys (most likely, attached by magnet) with super-poor optics quality, or ridiculously overpriced things, that still produce visible circle in frame.

OTOH, if you talk about regular-size camera lenses, it's quite hard to do feasibly, as N900's camera is at far left side of device. Thus, to mount it securely, one would need parts that extend much further to the left, that device body itself.

This thing looks like rather a project for special, attachable "mount-kit", than something one could bundle into body for everyday use. One of main goals of body replacement project is to provide superior-in-features body, that still is perfectly mobile (not much bigger than N90 0with mugen cover), when no external things are attached... Transforming into a feature behemot station, when all add-ons (external antennas & co) are connected ;)

Quote:

Originally Posted by malfunctioning (Post 1341777)
I wonder how much light might I get from some kind of IR headlamp in total darkness without even removing the IR filter from the N900 camera.

Not too much, sadly. Enough IR light goes through, if you light a diode directly into a sensor, but to see anything *illuminated* by IR (so, light is deflected by some object, back into N900's camera sensor), you need filter removed. Otherwise, even IR lamp from de-mobilized tank (seriously) doesn't illuminate well enough ;)

/Estel


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